They were booked by the Assam Police for their remarks against the Citizenship (Amendment) Bill at an event three days ago, even as the state witnesses protest against the legislation.The administration has also imposed prohibitory orders in parts of the city.

Police suo motu registered a case against them at the Latasil police station here under relevant sections of the (IPC) -- including 124(A) that deals with charges of sedition and 120 (B) dealing with criminal conspiracy, Guwahati Police Commissioner Deepak Kumar told reporters.

Gohain, Gogoi and journalist Manjit Mahanta have also been booked under IPC sections 121 and 123 -- relating to waging or trying to wage war against the government, he said.

Kumar said the case was registered against the trio for the comments they made against the bill during a meeting. The matter is under investigation, he said.

"A case has been registered against them. I am investigating what they spoke during a Nagarik Samaj meeting here on January 7. As of now, this is all that I can tell you," Kumar said.

The trio are part of a civil society group -- 'Nagarik Samaj' -- which is protesting against the bill.

Gohain, an eminent litterateur and retired Gauhati University professor, said he has come to know that a sedition case has been filed against him.